C H A P T E R 3 3
Anticholinergic agents
509
CHAPTER SUMMARY
■■
Anticholinergic drugs, also called parasympatholytic
drugs, block the effects of acetylcholine at cholinergic
receptor sites, thus blocking the effects of the
parasympathetic nervous system.
■■
Parasympathetic nervous system blockade causes
an increase in heart rate, decrease in GI activity,
decrease in urinary bladder tone and function, and
pupil dilation and cycloplegia.
■■
These drugs also block cholinergic receptors in the
CNS and sympathetic postganglionic cholinergic
receptors, including those that cause sweating.
■■
Many systemic adverse effects associated with the
use of anti–cholinergic drugs are due to the systemic
cholinergic blocking effects that also produce the
desired therapeutic effect.
■■
Atropine is the most commonly used anticholinergic
drug. It is indicated for a wide variety of conditions
and is available in oral, parenteral and topical forms.
■■
Individuals receiving anticholinergic drugs must be
monitored for dry mouth, difficulty swallowing,
constipation, urinary retention, tachycardia, pupil
dilation and photophobia, cycloplegia and blurring of
vision, and heat intolerance caused by a decrease in
sweating.
Knowing your strengths and weaknesses helps you to
study more effectively. Take a PrepU Practice Quiz
to find out how you measure up!
ONLINE RESOURCES
An extensive range of additional resources to enhance teaching
and learning and to facilitate understanding of this chapter may
be found online at the text’s accompanying website, located on
thePoint at
These include Watch and
Learn videos, Concepts in Action animations, journal articles,
review questions, case studies, discussion topics and quizzes.
Monitor for adverse effects: CV effects—tachycardia, heart
failure; CNS—confusion, dreams; urinary retention; GI
effects—constipation; visual blurring, photophobia.
Monitor for drug–drug interactions as indicated for each
drug.
Evaluate effectiveness of teaching program and comfort
and safety measures.
TEACHING FOR E.K.
• Anticholinergics are drugs that block or stop the actions
of a group of nerves that are part of the parasympathetic
nervous system. These drugs may decrease the activity
of your GI tract, dilate your pupils, or speed up your
heart.
• Some of the following adverse effects may occur:
•
Dry mouth, difficulty swallowing
: Frequent mouth care
will help to remove dried secretions and keep the
mouth fresh. Sucking on sugarless lollies will help
to keep the mouth moist. Taking lots of fluids with
meals (unless you are on fluid restriction) will help
swallowing.
•
Blurred vision, sensitivity to light
: If your vision is blurred,
avoid driving, operating hazardous machinery, or doing
close work that requires attention to detail until your
vision returns to normal. Dark glasses will help to protect
your eyes from the light.
•
Retention of urine
: Take the drug just after you have
emptied your bladder. Moderate your fluid intake while
the drug’s effects are the highest; if possible, take the
drug before bedtime, when this effect will not be a
problem.
•
Constipation
: Include fluid and fibre in your diet, and
follow any bowel regimen that you may have. Monitor
your bowel movements so that appropriate laxatives
can be taken if necessary.
•
Flushing, intolerance to heat, decreased sweating
: This
drug blocks sweating, which is your body’s way of
cooling off. This places you at increased risk for heat
stroke. Avoid extremes of temperature, dress coolly
on very warm days, and avoid exercise as much as
possible.
• Report any of the following to your healthcare provider:
eye pain, skin rash, fever, rapid heartbeat, chest pain,
difficulty breathing, agitation or mood changes
(a dose
adjustment may help to alleviate this problem).
• Avoid the use of over-the-counter medications, especially
for sleep and nasal congestion; avoid antihistamines, diet
pills and cold capsules. These products may contain drugs
that cause similar anticholinergic effects, which could
cause a severe reaction. Consult with your healthcare
provider if you feel that you need medication for
symptomatic relief.
• Tell any doctor, nurse or other healthcare provider
involved in your care that you are taking these drugs.
• Keep these drugs, and all medications, out of the reach of
children. Do not share these drugs with other people.
